Heart failure (“HF”) is a condition in which a subject's heart can't pump the needed amount of blood to the subject's other organs causing fluid to build up behind the heart. HF is one of the leading causes of death in the United States and a leading cause of poor quality of life in the human population over the age of 65. There are currently about 5 million or more cases of HF in the United States alone, with about 1 million of them hospitalized each year. As the population of subjects 65 years of age and older grows (i.e., amid the aging of the baby boomer generation), HF threatens a dramatic increase of morbidity and mortality, along with being a burgeoning drain on healthcare funds in the United States and other countries.
Some of many needs for HF subjects is accurately predicting, monitoring, and treating heart failure decompensation before an advanced disease stage is reached. Heart failure, and more particularly heart failure decompensation, may signify the drawing near of death or, at the very least, the need for extensive hospitalization intervention. With sufficient warning, steps including drug or electrical stimulus therapy can be initiated or adjusted to save the HF subjects from either of these advanced HF consequences. Unfortunately, the time associated with typical HF detection is often too late in the disease process to prevent significant clinical intervention (e.g., hospitalization) or death.